Telescope Observations And Life Events

Roger Ivester: Observer from North Carolina

Many amateurs consider NGC 6118, also known as “The Blinking Galaxy” to be the most difficult object in the entire Herschel 400 list.

I remember first reading about this galaxy almost 30 or more years ago in an astronomy publication, possibly the Astronomical League, Reflector Magazine. This article concerned an amateur who was just beginning his quest to see the entire list, and “as bad luck would have it” chose NGC 6118 as his first object. This galaxy is known as “The Blinking Galaxy” due to it seemingly appearing and then vanishing, similar to a few planetary nebulae. So, after consulting with other amateurs, he was told that NGC 6118 was extremely faint and was possibly the most difficult object in the entire Herschel 400 list.

I was working on the Herschel’s at the time (1994-1995) while reading this article, but had not attempted to locate and observe this galaxy. I had completed about 150 or more of the objects, but due to light pollution and a very poor southern view was forced to cancel my efforts.

However, since that time, I’ve just not been able to forget about galaxy NGC 6118 and the article, concerning its difficulty.

So, on August 5, 2023, shortly after sunset, the skies looked pretty good. The humidity was very high at 91%, which in-part caused very poor transparency. And I was also having to look over the town of Boiling Springs, with lots of light pollution. It was also a bit late in the year, as the galaxy was already too far to the west.

March, April and May 2024

I also attempted two very early morning observing sessions in March and April of 2024, from my suburban backyard, but again without success. A dark site is really needed to observe any low-surface-brightness galaxy, especially one as dim and faint as NGC 6118.

However, traveling to a dark-site has been over for me now for many years. The disassembly of a heavy equatorial mount and handling a large solid-tube Newtonian, loading, driving, unloading, reassembly, and then having to do it all again, became just too much. I will continue to do my best from the backyard.

Many years ago, I assembled light-block system, made of heavy-duty automotive-marine fabric. This simple, but effective structure has helped me on many occasions over the years to see difficult and faint deep-sky objects. The light-block system is especially helpful in some areas of the southern sky, where light pollution is significant. It’s easy to set up and take down. When the fabric is removed and folded for storage, the steel post and plastic-coated wires remain and are hardly noticeable.

I attribute my ability to finally see NGC 6118 was due to blocking a very bright LED carport light less than 1/8 mile away. This light was shining directly toward my backyard, and brightening up the area of my telescope and observing location significantly.

Saturday morning; May 11th 2024 @ 1:00 AM, with a 5.0 NELM overhead, but far less in the sky near NGC 6118, due to overlooking the town of Boiling Springs.

With a bit of difficulty and after almost an hour of careful observing, I was finally able to see the galaxy. My portable “make-shift” observatory was the answer to finally seeing this faint and difficult object from my suburban backyard.

I really don’t think this galaxy would be that difficult from a dark-site, and with my 10-inch Newtonian. However, as I’ve mentioned previously, my days of traveling with a telescope have been over for a few years now. I just love the convenience of my backyard and seeing a galaxy this faint, proves that a suburban backyard can still allow effective deep-sky observing.

Description: A tiny and subtle brighter middle, which resembles that of a planetary nebula. And like so many planetary nebulae, when using direct vision, vanishes or winks out. I now know why NGC 6118 is known as “The Blinking Galaxy.” The galaxy has a very faint and diffuse halo with mottling, which is oriented NE-SW.

Roger Ivester: Observer from North Carolina

Telescope: 10-Inch f/4.5 EQ Newtonian

Sketch Magnification: 142x 

FOV: 0.46

NELM: 4.8 

So during the months of October and November 2023, three observing sessions and more than six-hours at the eyepiece, I was finally successful in seeing this galaxy.

So by own authority as an amateur astronomer, which is no authority, I’m naming this galaxy: “The Invisible Galaxy.” 

A difficult and very faint low-surface brightness galaxy, using my 10-inch Newtonian. After three nights with poor transparency, and more than six-hours of observing I was finally about to make my final sketch, as following.  

The first thing to look for is a triangle of three mag. 9 stars, with the galaxy being just to the N. 

The galaxy appears as a mere brightening in the sky, but upon careful observing over the three nights, the glow of the galaxy halo became enlarged, and elongated NNW-SSE. 

There is an extremely faint, and very subtle brightening in the middle. A faint star is visible near the center and a mag. 13 star is fairly easy to see just to the W.  

In the following sketch, note the pair of faint and close double stars in the NW edge of the field. 

Using a 76mm (3-inch reflector) at 13x with a 3º field of view:  

I could see both NGC 1502 and most of Kemble’s Cascade, a bright chain of stars cascading from the NW toward the cluster.   At this low power, NGC 1502 appears as a faint patch with several bright stars noted with a triangular shape. 

When increasing the magnification to 70x, I could count 8-10 stars, and double star Struve 485 was very easy.  The central region of the cluster appears a bit hazy due to faint stars in the background, too faint to be resolved with the small scope.   Roger 

 

JANUARY 2012 OBSERVERS CHALLENGE – NGC-1502  

The great globular cluster, M13 is located high overhead for observers in the northern hemisphere during the summer months, allowing for excellent viewing.  When observing this cluster back in 1977 with my 4 1/4-inch f/10 reflector, the most I could see was a moderately bright ball of unresolved stars.    

While observing M13 with the small reflector, I was unaware of the three dark lanes cutting into the SE edge of the cluster, known as the propeller.  I had never heard of the propeller at that time, but this scope was far too small to see this very faint feature.  However, thirty two years later in May of 2009 using a much larger telescope, I was finally able to see the three dark-lanes.     

A 10-inch telescope “might be considered the minimum aperture” required to see this most unique feature.  If you have plans to observe the “elusive propeller” a magnification of around 200x seems to be the optimum.  

The propeller challenge seemingly became popular due to Walter Scott Houston, columnist and writer of “Deep-Sky Wonders” suggesting that observers look for it.  

Houston first wrote about the propeller in the July 1953 edition of “Sky & Telescope magazine.”  He brought it up several more times through the years, however,  it has been only in recent times that the propeller has gained much attention in the amateur astronomy community. 

Lord Rosse mentioned three dark rifts in the 1850’s, and T.W. Webb in “Celestial Objects for Common Telescopes” noted that the lanes were seen by Buffham, using a 9-inch reflector. 

John Bortle saw the lanes in 1980 using a 12.5-inch reflector, and Dennis di Cicco saw them easily with the 12-inch f/17 Porter telescope during Stellafane in 1981.  (Source: “Deep-Sky Wonder’s” By Walter Scott Houston, selections and commentary by Stephan James O’Meara.  Sky Publishing Corporation, Cambridge Massachusetts)  

In May of 2009, I was able to observe the propeller with both 10 and 12-inch Newtonian’s.  My first sighting of the propeller came when using a friends 12-inch from the southern rim of the South Mountains in North Carolina.  I would rate this site as very good with a NELM of 6.0 (at the zenith) and maybe even better on an excellent night.  

The propeller was fairly easy to see with the 12-inch f/5 reflector from this location.  However, seeing the propeller from my suburban backyard and 10-inch f/4.5 Newtonian, was possibly seen only using my imagination.  🙂

The following sketch was made using Steve Davis’ Meade 12-inch f/5 reflector at 190x, just off Moore Mountain Road in Rutherford, County.  

The sketch was made with a No. 2 pencil and a blank 5 x 8 note card.  The colors were inverted using a scanner.